Portion of a holder for test tube



FIG. 1 is a front, top and right side perspective view of a portion of a holder for test tube showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a right side elevational view thereof.

The broken lines are included for the purpose of illustrating portions of the portion of a holder for test tube that forms no part of the claimed design. 

We claim the ornamental design for a portion of a holder for test tube, as shown and described. 